1. Field Of The Invention
This invention relates to a mining machine, and more particularly, to a continuous miner which includes a mobile frame assembly and a boom assembly pivotally secured to the mobile frame assembly by a plurality of connectors which distribute the load placed on the boom assembly as the boom assembly is pivoted upwardly from the mobile frame assembly evenly throughout the boom structure, and to a dust collecting system for collecting airborne particles produced as a material dislodging head mounted on the end of the boom assembly dislodges material from a mine face.
2. Description Of The Prior Art
In underground mining, it is well known to provide a continuous mining machine which includes a material dislodging head positioned on the front end of the mining machine for dislodging material from a mine face. The dislodged material is conveyed rearwardly of the mining machine by a conveying system positioned on the continuous mining machine. The continuous mining machine is designed to continuously advance and dislodge material being mined to form an entry or tunnel in the material seam.
Various types of continuous mining machines having different types of tilting of pivoting mining heads are known. U.S. Pat. No. 2,986,384 discloses a mining machine having tiltable, dual mining heads. U.S. Pat. Nos. 3,479,090 and 3,495,876 disclose continuous mining machines each having a pivoting structure for supporting a mining head.
U.S. Pat. No. 3,498,676 discloses a continuous mining machine having a mining head that is positioned at the top of the mine face. The mining head is advanced into the mine face and traversed downwardly through the mine face to cut and break the material out of the mine face. The mining machine is supported on traction treads by which the machine is propelled forwardly to advance the mining head into the mine face.
U.S. Pat. No. 3,499,684 discloses a mining machine with a mining head positioned at the forward end of the machine. Traction means propels the mining machine, and gathering means collects the mined material and transfers the material to a conveyor for moving the mined material to the rear of the machine. The mining head is positioned on a boom that is movable upwardly and downwardly about the transverse axis of a pivot support on the machine main frame.
U.S. Pat. No. 3,516,712 discloses a continuous mining machine with a transverse rotary mining head for mining material from the entire area of the mine face by traversing the mining head through the mine face.
U.S. Pat. No. 3,874,735 discloses a continuous mining machine adapted for low overhead coal seams having a relatively small diameter cutter head of the non-oscillating or fixed head type driven by chains that also cut coal and convey it rearwardly to a gathering head mounted on the front of the machine. The gathering head carries a pair of counter-rotating discs having veins cooperating with conveyor fences for sweeping and discharging coal to a conventional conveyor mounted on the machine chassis.
U.S. Pat. No. 3,966,258 discloses a mining machine having a disintegrating head carried on the front end of the machine by a pivotal link arrangement.
In continuous underground mining, it is also known to provide a mining machine which includes a dust collecting system mounted thereon for collecting airborne dust particles produced as the mining machine cutting or dislodging head operates. The dust collecting system provides a relatively clean environment for the mining machine operator.
U.S. Pat. No. 3,712,678 discloses a continuous miner which is provided with a dust collecting system comprising boom-carried ducting adapted to receive dust-entrained air adjacent and rearwardly of the mining head. The mining machine chassis carries ducting which is operable to alternatively discharge the air to opposite sides of the machine. Counter-rotating centrifugal fans mounted in the boom-carried ducting draw dust-entrained air to such ducting whereby the air flows therethrough to the chassis-carried ducting. Scrubbers or cleaners are operatively associated with the boom-carried ducting for removing larger dust particles from the air.
U.S. Pat. No. 3,810,677 discloses a mining machine having a boom enclosed dust collector assembly for use in a coal mining operation wherein the dusty air from a mining operation is gathered directly from the operation, collected in the mining machine boom and selectively wetted and separated by centrifugal processing into a coal slurry for disposal. The clean air is exhausted to atmosphere. The coal slurry is discharged from the mining machine boom through a flexible hose which lies on the ground along a side of the machine.
U.S. Pat. No. 4,380,353 discloses a dust control system for a mining machine comprising a ductwork system having intakes adjacent the cutter head of the mining machine. A fan draws air through the ductwork system, and a flooded bed scrubber in the ductwork system upstream from the fan entrains the dust in droplets of water. The dust laden water is pumped to a point adjacent the cutting head.
U.S. Pat. No. 4,557,524 discloses a continuous mining machine having a dust control system which includes a generally rectangular intake duct section associated with the boom and a generally rectangular fixed duct section mounted on the vehicle. A transition section is connected to the intake of the fixed duct section. The transition section consists of a two piece arrangement wherein each piece is hinged to the intake duct section and is capable of slidingly engaging the fixed duct section at the end thereof adjacent the boom to sealingly couple the intake duct section to the fixed duct section as the boom swings upwardly and downwardly.
Although the prior art continuous mining machines include various types of cutting heads pivotally mounted on the mining machine, there is a need for an improved mining machine having a boom assembly pivotally connected to the mining machine frame assembly by a plurality of connectors which distribute the load on the mining machine boom assembly as it is pivoted upwardly from the mining machine frame assembly evenly throughout the boom assembly structure. Further, there is a need for a simple, efficient dust collecting system whereby dust produced as a dislodging head dislodges material from a mine face is passed through a boom assembly hollow interior portion to a dust collecting system mounted on the mining machine frame. A portion of the boom assembly forms a pivoting joint with a portion of the dust collecting system positioned on the mobile frame assembly to allow airborne dust particles to be withdrawn from the mine face as the boom assembly pivots upwardly and downwardly relative to the mobile frame assembly.
In another embodiment of the invention, two portions of the boom assembly form pivoting joints with portions of the dust collecting system positioned on each side of the mobile frame assembly to allow airborne dust particles to be withdrawn from the mine face as the boom assembly pivots upwardly and downwardly relative to the mobile frame assembly.
Twin ducts of the collecting system meet the boom on each side of the mining machine and extend rearwardly along each side of the mobile frame assembly. One of the twin ducts passes between the conveying reach and the return reach of the conveying system to join with the other duct to allow a single fan to withdraw airborne dust particles from the mine face.